Conventionally, a solar heat collecting device is proposed, which is designed to collect sunlight by a trough type reflector having a parabolic section on a heat collecting pipe, and to transmit energy to a heat medium passing through the inside of the heat collecting pipe (see, for example, patent document 1).
Such conventional solar heat collecting device includes various measures for raising the light collecting efficiency, and for example, the solar heat collecting device of patent document 1 proposes to be provided with a structural element for converging sunlight in the inner tube, in the outer pipe covering the outer circumference of the inner pipe transmitting energy to the heat medium passing through the inside, by forming a heat insulating space.
For example, in a solar heat collecting device of patent document 2, it has been proposed to include a sun tracing mechanism for oscillating an oscillation axis for oscillatably supporting a reflector and a heat collecting pipe so that the reflector may be directed to the direction of the sun.